checking large scale linear programming solution with a given accuracy

*To*: mathgroup at smc.vnet.net*Subject*: [mg113389] checking large scale linear programming solution with a given accuracy*From*: Mala Jozsef <mala_jozsef at freemail.hu>*Date*: Tue, 26 Oct 2010 05:35:53 -0400 (EDT)

Dear Group, NMinimize sometimes gives a[39,3]->1.0000000000000178` as a solution instead of 1 when dealing with large scale linear programming task. Moreover, Mathematica sometimes gives a "solution" when there is no feasible one. Here is an example: In[207]:= NMinimize[{1,x+y>=0,x+y<=-1,Element[x,Integers]},{x,y}] Out[207]= {1.,{x->-1,y->0.}} I would like to check a solution with a given accuracy, say, some digits. Is there any "almost built in" or easy solution? Thanks in advance. Jozsef